Blood handling procedure

ABSTRACT

COAGULATION OF BLOOK IS INHIBITED AND COAGULATED BLOOD IS DECOAGULATED BY IMPRESSING DIRECT CURRENT ELECTRICAL ENERGY ON THE BLOOD AT A CATHODE POTENTIAL SUFFICIENT TO DECOAGULATE BUT INSUFFICIENT TO CHEMICALLY BREAK DOWN THE BLOOD.

United States Patent 3,565,774 BLOOD HANDLING PROCEDURE Harry T. Anderson, Clarendon Hills, Ill., assignor to Swift & Company, Chicago, 111., a corporation of Delaware No Drawing. Filed Aug. 29, 1968, Ser. No. 756,300 Int. Cl. B01k 1/00; C14c 3/34 US. Cl. 204131 5 Claims ABSTRACT OF THE DISCLOSURE Coagulation of blood is inhibited and coagulated blood is decoagulated by impressing direct current electrical energy on the blood at a cathode potential sufficient to decoagulate but insuificient to chemically break down the blood.

SPECIFICATION This invention is directed to the control of blood coagulation. More particularly, this invention relates to the decoagulation of coagulated blood and the suppressing of coagulation of the blood during storage and further processing. In addition, this invention concerns a method of maintaining blood as a homogeneous liquid by proper introduction of direct current.

Generally speaking, blood will coagulate within a few minutes after leaving a vein or artery. Coagulation rates, however, vary from one test animal to another. The coagulated blood is difiicult to process as large, rather firm masses of coagulated blood Will block pumps and pipes used to convey the blood from one location to another. When this occurs, drastic agitation, such as an air lance or high pressure Water hose, is required to break up the coagulated mass and cause its movement through the equipment.

Furthermore, coagulation prevents the discharge of blood through orifices, such as are present in spray dryers. The coagulated blood, adhering to surfaces of processing equipment, prevents uniform processing of the blood. Large masses of coagulated blood can form around shafts and other moving parts of process equipment and are extremely difficult to remove. In conventional drying equipment it is not practical to remove large firm masses of dried blood from the dryer, shaft and other .moving parts. This problem decreases the efficiency of the overall operation.

Coagulation of blood not only causes a waste of material but also causes problems in the cleaning of equipment. Blood also tends to recoagulate in sewer lines and also adds to the load of waste treatment plants.

One method of attacking this problem has been the use of chelating agents. It is generally well known that sodium citrate and other chelating agents will decrease coagulation rates or prevent blood coagulation to some extent. In some blood processing systems, it is ditficult to introduce chemical anti-coagulants uniformly. This results in incomplete control of coagulation. It is particularly difficult where large quantities of blood must be handled quickly, such as in packing house operations.

It is, accordingly, one object of this invention to provide a practical means for controlling blood coagulation.

Additional objects, if not specifically set forth herein, will be readily apparent to those skilled in the art from a reading of the detailed description of the invention which follows.

In general, this invention is concerned with the treatment of blood so as to either suppress the coagulation of blood or to decoagulate blood that has coagulated. In order to cover both concepts, applicant has used the words to control blood coagulation to mean either the suppres- 3,565,774 Patented Feb. 23, 1971 sion or inhibition of coagulation or the decoagulation of coagulated blood.

Generally speaking, the objects of this invention are accomplished by the process of impressing direct electrical current through the blood so as to produce a substantially uniform but adequate cathode potential at all areas of the tank walls. Generally, in establishing the electrical circuit, an anode is placed in contact with the blood and the receptacle holding the blood will be used as the cathode. It is mentioned at this time that for the sake of brevity, the cathode will be defined as the tank in the examples in the description that follows. However, an equivalent embodiment would be the use of rods or sheets of metal placed sufliciently close to the walls of the receptacle which would act as suitable cathodes. This embodiment would be used when the walls of the receptacle are generally poor or non-conductors of electrical current.

In the study of blood coagulation, it is noted that the blood first appears to be a rather homogeneous mass. Later on, separations tend to take place. In large vessels distinct separations become quite noticeable. In the lower region of a vessel, large, uniform, rather firm-textured masses form. Above ths area accumulations of fibrin are observed. These accumulations of fibrin are normally converted into fibrous masses. Some fibres may become three to four feet in length and about to about /8" in diameter. As these fibres continue to develop and increase in number, a mat of fibres is formed. This mat may increase to more than a foot in thickness, depending upon the depth of the material in the vessel.

In slaughterhouse operations, the blood coagulates rapidly when in contact with most surfaces that are poor conductors of electrical current such as glass, plastics and tile. In regard to metal surfaces, the blood will generally coagulate more slowly. In addition, actual coagulation rates will depend upon the metal surfaces exposed to the blood. For example, rusty tanks tend to coagulate the blood more rapidly than very clean tanks.

It has been found that proper distribution of direct current can control the blood coagulation problems, especially those in packinghouse operations. The source of electrical current can be either galvanic or impressed direct current. When exposing the blood to the action of electrical current, high current densities near the anode should be avoided as they tend to break down and char the blood. For example, it is possible to char and break down the blood using potentials as low as two volts if there are high local current densities near the anode. On the other hand, a potential of 20 volts or higher will not char blood if local current densities are lower near the anode. Also, it is possible to produce excessive current densities near a cathode in other regions within the blood tank by improper design. However, by reading of the description of the invention that follows, it will become readily apparent to those skilled in the arts how to design the desired cell. In this connection, it is pointed out that it isnt necessary to design a symmetrical electrical cell to prevent excessive current densities. In some cases most effective decoagulation was produced in a nonsymmetrical cell.

In designing the electrical circuit, careful consideration of the electrodes is important. Generally speaking, the anode can be any of the typical metals used in anode construction. It is preferred to use a highly siliconed-iron anode inasmuch as such material has a -very low attrition rate. However, for purposes of this invention, any material capable of carrying a current is theoretically possible to serve as the anode. Additional factors that should be considered when designing the electrical circuit include the electrode profile, surface conditions, resistance value of electrode material, distance between electrodes, number of electrodes, electrode potentials and the geometry of electrode placement configuration, especially in cells with multiple anodes and/or cathodes. Excessive anode potential levels will cause breakdown of the blood protein as evidenced by release of ammonia in the cell. Suitable anode potentials are dependent upon the cathode potentials. As any given cathode potential is increased the optimum anode potential should decrease in order to prevent the blood from decomposing.

The anode also must not operate at a potential that substantially polarizes the cathode. Polarization restricts current flow producing an excessive exertion in the blood. The resulting increase exertion throughout the cell may be suflicient to release ammonia from the blood proteins. In general, it may be stated that an electrical cell designed so as not to produce excessive cathode potentials, polarization of cathodes or excessive local current densities will effectively decoagulate the blood without decomposing the proteins.

An electrical cell operating at low anode and cathode potentials will retard coagulation of fresh blood. Operating a cell at higher potentials will accelerate coagulation and cause a separation of the serum from blood at the cathode.

In slaughterhouse systems, the blood-holding tanks are normally comprised of carbon steel, stainless steel or other metal and the walls of these tanks are quite suitable for acting as the cathode in the electrical cell. It is again emphasized however that the invention is not restricted to using the walls of the vessel as the cathodes since independently placed cathodes (usually placed close to the walls of the vessel) will function adequately as a cathode for establishing an electrical circuit.

At this point it perhaps should be brought out that the physical location of the anode is important in that at least one of the anodes must cut through the surface of the blood. It was found that if all the anodes were submerged, the lower region of coagulated blood in the holding tank decoagulated but not all of the fibrin mat tended to liquefy. While fibrin carries an electrical current well, air spaces in the fibrin mat do not permit uniform current distribution throughout the mat. This prevents suificient exertion to liquefy all of the mat. Accordingly, in carrying out the process of this invention, it was found that at least one anode should have a portion of its active surface submerged to correct this problem. It might be stated in passing that when rods are used for the cathode instead of the walls of the tank, a portion of the cathode should also extend above the surface of the blood. These separate cathodes should have essentially the same polar value as the tank or they might have a higher polar value but generally speaking should not be of lower polar value than the tank.

The following examples are set forth as illustrated em- EXAMPLE I A steel tank of about 28 long by 54" wide and deep was filled approximately full with cattle, hogs and sheep blood. The steel surfaces of the tank were in good condition but mill-scale still covered much of the metal surface. A high silica-iron anode of 1 /2" diameter by 9" long was positioned so that the anode was submerged in the blood. An electrical wire was connected to a high point of the tank wall, which acted as the cathode, and grounding this to the rectifier completed the circuit. Using a rectified DC current to energize the anode, various voltages were applied. At 12 volts, clouds of ammonia rose from this cell. At 8 volts, very little, if any, ammonia was released from the blood protein. At 6 volts, no ammonia was released. Operating the anode at 6 volts down 4- to a level of 2 /2 volts prevented the blood from sticking to the tank walls.

EXAMPLE II A steel tank having the dimensions of about 11' x 10' x about 6 deep was filled with about 4 feet of cattle and lamb blood. A 2 diameter anode 60" long of high silicairon was placed in the blood-holding tank such that the bottom of the anode was approximately 16" from the bottom of the tank. Approximately 30" of the anode extended above the surface of the blood. It was positioned such that the anode was 3 from one side and 5' from the other side. The anode was operated at voltages ranging from 20 to 30 volts without releasing ammonia from the coagulated blood. Most of the blood entered the tank less than an hour before the tank was emptied. Prior to that time the anode was not in contact with the blood. But in that short exposure time (usually about 20 to 30 minutes) 50% of the coagulated blood was decoagulated with anode potentials at 20 to 30 volts.

EXAMPLE III Two sheets of steel having dimensions of 12" x 60" and A2" thick to function as the cathode were laid on a tile floor of a blood-collecting vessel. A 2" diameter x 60" long anode was placed on the tile floor between the two steel sheets at a distance of approximately 6 from their edge. A rectifier was connected to the anode and cathode to complete the circuit and it was found that operating the anode up to about 6 volts reduced the coagulation rate of blood.

EXAMPLE IV Two high silica-iron anodes 1%" diameter x 60" long with 3 anodes 1 /8" diameter x 9" long were connected to a rectifier and placed inside a steel tank containing cattle, hog and lamb blood. The anodes were placed such that one of the anodes cut through the surface of the blood. To complete the circuit, the rectifier was attached to the wall of the steel tank. The tank was 28' long x 5 wide x 5' deep. The three small anodes were spaced equal distance apart starting approximately 6' from the end of the tank. They were placed 15" above the low point of the tank and approximately 14" from the tank wall. The tank contained no mill-scale but most of the surface was covered with rust. An anode potential of 10 to 15 volts did not release ammonia while decoagulating the blood. However, a fibrin mat formed at the surface and all of this mat did not dissolve. However, the mat thickness was reduced from about 17 down to about 3" or 4". The lower uniform layer was completely liquefied. Placing another high-silica iron anode 1 /2 diameter x 60" long and perpendicular position 24" from the end of the tank liquefied most of the remaining mat. This anode extended above the top of the tank so it always cut through the product level.

EXAMPLE V A 1 /2" diameter x 60" anode centered and perpendicular positioned in an 8 diameter tank 14' deep was spaced 28" off the bottom of the steel tank so as to produce uniform current distribution. The tank was covered on the inside with rust. Anode potentials ranging from 20 to 30 volts were utilized to decoagulate cattle, lamb and beef blood. Filling the tank to a depth of about caused a current output of about 15 amperes. After an exposure of less than about 15 minutes, initial visible evidence of decoagulation was produced. A discrete liquid formed at the interphase of the cathode which in this case was the tank. This grew in dimension until the remaining fibrin mat pulled away and tilted in toward the anode. The liquefied fibrin increased in dimension uniformly at the cathode. Later liquefying of fibrin started at the anode but increased slowly at the anode until the liquefied fibrin forming at the cathode advanced to midpoint between the cathode and anode. This reaction required 40 minutes to complete even though blood had been allowed to completely coagulate before current was impressed upon the anode. Only remnants of fibrin mats remained on the surface. Lower regions of coagulated masses were com pletely decoagulated and were water-thin. Filling the tank above the upper level of the anode did not produce good results and again was evidence that the anode must cut through the surface of the blood to completely liquefy fibrin mat at surface.

EXAMPLE VI A steel trough was placed on a tile floor of a bloodcollecting vessel. Two 1 /8 diameter anodes of about 9" in length placed approximately 3" above the trough floor in a vertical position were utilized. The walls of the trough were used as the cathode and the circuit was completed by means of a rectifier. An anode voltage of 2 /2 to 4 volts reduced coagulation substantially. Upon grounding of a grating above the shallow blood-collecting pit to the trough, coagulation was further reduced. Coagulated masses formerly hanging from the grating liquefied. Retaining decoagulated blood in the trough almost prevented fresh blood from coagulating in areas remote to trough. From these tests it is apparent that coagulation can be controlled by direct current application to almost any desired extent by careful design of the cell.

From the above tests it is obvious that coagulation can be controlled through several procedures and to varying degrees of control. For example, one can let blood coagulate. After sufficient coagulation is produced, the application of current to the coagulated blood will cause it to decoagulate. At this point, fresh blood entering the system will not coagulate if volume added is not at excessive rate for cell size.

Impressing a current to control coagulation problems does not alter the pH values. In addition, electrical decoagulation does not alter or prevent the use of the blood as a raw material in adhesives. Furthermore, the blood is acceptable for all other established uses.

Obviously many modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof, and, therefore, only such limitations should be imposed as are indicated in the appended claims.

I claim:

1. A method of controlling the coagulation of blood contained in a receptacle which comprises impressing a direct electrical current through said blood between at least one anode and a cathode in contact therewith, at least one anode being stationed such that a portion of the active surface of the anode is submerged below the blood level and at a cathode potential sufficient to decoagulate any clotted blood and sufiicient to suppress coagulation but insufficient to promote decomposition of the blood.

2. The method of claim 1 wherein the blood has coagulated prior to the treatment with electrical current.

3. The method of claim 1 wherein the blood has not substantially coagulated prior to treatment with electrical current.

4. The method of claim 1 wherein the receptacle serves as the cathode to complete the circuit to the power source.

5. In the method of claim 1, the improvement comprising the use of a plurality of anodes which cut through the surface of the blood to liquefy fibrin mat at the surface.

References Cited UNITED STATES PATENTS 2,450,457 10/1948 Grotenhuis 18-12 2,600,107 6/1952 Gelfand et al. 2O4l3l 3,140,714 7/1964 Murphy Jr. et al. l28214 JOHN H. MACK, Primary Examiner A. C. PRESCOTT, Assistant Examiner US. Cl. X.R. 

